Distributor housing and plate assembly with rotatable clamping means

ABSTRACT

An ignition distributor for a road vehicle, wherein the hollow casing of the distributor is formed internally with a support surface, and the contact breaker assembly base plate of the distributor is engaged with the support surface. A pair of cam members are engaged with the base plate and the casing, and are operable upon rotation, to clamp the base plate against said support surface.

[54] DISTRIBUTOR HOUSING AND PLATE ASSEMBLY WITH ROTATABLE CLAMPINGMEANS [75] Inventor: Gordon Keeley, Sutton Coldfield,

England [73] Assignee: Joseph Lucas (Industries) Limited,

Birmingham, England 22 Filed: .luly20, 1971 21 Appl.No.: 164,313

[30] Foreign Application Priority Data July 23, 1970 Great Britain..35,694/70 [52] U.S. Cl ..200/19 R, 200/31 DP, 292/202, 292/241 [51]1nt. C1. ..H01h 9/02, E05c 3/04, E05c 3/14 {58] Field of Search..200/19R, 19 A, 30, 31, 31 DP; 292/202, 241, 256.5

[56] References Cited UNITED STATES PATENTS 2,889,418 6/1959 Kline..200/30 X 1 Feb.6,1973

2,489,775 11/1949 Haubert ..200/31 2,546,710 3/1951 Aldridge ..200/19 A2,671,829 3/1954 Bales ..200/31 2,739,195 3/1956 Bales ..200/19 A2,515,507 7/1950 Glitsch 292/241 X 2,551,408 5/1951 Amundson ..292/2022,900,678 8/1959 Curtis 292/202 X 3,575,452 4/1971 Blomgren ..292/202FOREIGN PATENTS OR APPLICATIONS 554,608 7/1943 Great Britain ..200/31Primary Examiner-J. R. Scott Attorney-Holman & Stern [57] 7 ABSTRACT Anignition distributor for a road vehicle, wherein the hollow casing ofthe distributor is formed internally with a support surface, and thecontact breaker assembly base plate of the distributor is engaged withthe support surface. A pair of cam members are engaged with the baseplate and the casing, and are operable upon rotation, to clamp the baseplate against said support surface.

4 Claims, 6 Drawing Figures DISTRIBUTOR HOUSING ANDPLATE ASSEMBLY WITHROTATABLE CLAMPING MEANS This invention relates to ignition distributorsfor road vehicles.

A distributor according to the invention includes a hollow casing formedinternally with a support surface, a contact breaker assembly base plateengaged with said support surface and at least one cam member engagedwith the base plate and the casing and operable to clamp said base plateon said support surface.

Preferably said support surface is in the form of a peripheral inwardlydirected shoulder integral with the casing.

Conveniently a pair of cam members are provided acting between thecasing and the base plate.

Preferably the or each cam member is engaged with the base plate and isrotatable relative to the base plate and the casing to engage a camsurface on the cam member with a mating surface on the casing.

Desirab ly said mating surface is defined by part of a peripheral groovein the inner surface of the casing.

One example of the invention is illustrated in the accompanyingdrawings, wherein FIG. 1 is a fragmentary sectional view of the casingof an ignition distributor,

FIG. 2 is a plan view, to a reduced scale of the base plate of thedistributor,

FIGS. 3 and 4 are plan and side elevational views respectively of .a cammember for securing the base plate to the casing,

FIG. 5 is a fragmentary sectional view illustrating the base plate ofFIG. 2 secured to the casing of FIG. 1, and

FIG. 6 is'a plan view of the part of the arrangement shown in FIG. 5.

Referring to the drawings, the casing 11 of the distributor is cast isan aluminum alloy, and includes a peripheral inwardly directed rib 12the upper surface of which defines a peripheral shoulder 13 at rightangles from a base plate 15 (FIG. 2). The base plate 15 is circular, andis formed with a centrally disposed hole 16 through which in use, thecam shaft of the distributor ext ends. The diameter of the base plate 15is substantially equal to the internal diameter of the casing 11,

and so the plate 15 can be inserted into the casing 11 and will seat onthe shoulder 13. Thus the shoulder 13 constitutes a support surface forthe base plate 15. In order to retain the base plate 15 in position inthe casing 11, the base plate 15 is formed with a pair of radiallyinwardly extending'slots l7 spaced apart around the periphery of thebase plate 15 by 170. Engaged in each of the slots 17 is a respectivelocking cam member 18 (FIGS.3and 4).

Each of the cam members 18 includes a substantially cylindrical majorportion 19 including a mid-portion 21 of reduced diameter. The diameterof the portion 21 is substantially equal to the width of the slots 17 inthe base plate 15, and is of axial length substantially equal to thethickness of the plate 15. The diameter of the remainder of the portion19 of each cam' member 18 is greater than the width of the slots 17, andso the cam members 18 can be inserted into the respective slots 17,theportions 21 of the cam members being received in the slots 17, andthe portions of greater diameter at the ends of the portions 21 servingto retain the cam members 18 against axial movement relative to the baseplate 15. Since the diameters of the portions 21 are substantially equalto the widths of the slots 17, then the cam members 18 can be rotatedrelative to the plate 15. The portions 19 of the cam members 18 are eachformed with a through bore 22 of hexagonal cross section for receivingan operating tool, for example, an allen key. The portion of each of themembers 18 which lies in use beneath the plate 15 is formed with aneccentric cam lobe 23' having a pair of oppositely directed rampsurfaces 24, 25. The ramp surfaces 24, 25 increase in heightprogressively around the periphery of the member 18 from a minimumheight at a pair of diametrically opposite points where the rampsurfaces 24, 25 merge with the portion 19 of the member 18, to a maximumheight where the two ramp surfaces 24, 25 merge with one another. Inaddition, the ramp surfaces 24, 25 increase in height progressively froma minimum at their outer peripheral edge, to a maximum at their rootsadjacent the portion 19.

In order to assemble the base plate 15 to the casing 11, the cam members18 are engaged in their respective slots 17, and are rotated to aposition wherein the cam lobes 23 are inwardly directed. The base plate15 is then inserted into the casing 11, so that the periphery of thebase plate 15 seats on the shoulder 13. The cam members 18 are thenrotated relative to the plate 15 and the casing 11, so that one or otherof the surfaces 24, 25 of the cam members 18 engages the surface 14a onthe casing 11. Sufficient force is applied to the cam members 18, whenrotating the cam members 18 relative to the plate 15, for the cam actionbetween the surface 14 and the surfaces 24, 25 to clamp the periphery ofthe base plate 15 firmly against the shoulder 13. In addition toclamping the plate 15 in an axial direction onto the shoulder 13, theaction of the cam forms 23 and the surface 14 serves to move the cammembers 18 radially with respect to the base plate 15, until theportions 21 of the cam members 18 abuts against the closed ends of theslots 17, whereupon the plate 15 is held against lateral movementrelative to the casing 1 I, in addition to being held against axialmovement relative to the casing 11. I

The contact breaker assembly of the distributor is mounted on the baseplate 15 in a conventional manner, and can of course be assembled to thebase plate 15 prior to insertion of the base plate 15 into the casing11. The cam shaft of the distributor extends through the central hole 16of the base plate 15, and rotation of the cam shaft in use operates thecontact breaker assembly of the distributor in the conventional manner.

It will be appreciated that, although two cam members are preferred, oneor more than two cam members could be provided.

I claim:

1. An ignition distributor for a road vehicle, including a hollowcasing, a support surface on the interior of the hollow casing, acontact breaker assembly base directed shoulder integral with thecasing. 3. A distributor as claimed in claim 1 in which the surface ofthe casing engaged by the clamping device is defined by part of aperipheral groove in the inner surface of the casing.

4. A distributor as claimed in claim 1 in which there is provided asecond clamping device.

1. An ignition distributor for a road vehicle, including a hollowcasing, a support surface on the interior of the hollow casing, acontact breaker assembly base plate engaged with said support surface, arotatable clamping device, and means rotatably mounting the clampingdevice on the base plate, the clamping device including an inclinedsurface engaging the casing, whereby rotation of the clamping devicerelative tO the base plate and the casing causes the device to clamp thebase plate on said support surface.
 1. An ignition distributor for aroad vehicle, including a hollow casing, a support surface on theinterior of the hollow casing, a contact breaker assembly base plateengaged with said support surface, a rotatable clamping device, andmeans rotatably mounting the clamping device on the base plate, theclamping device including an inclined surface engaging the casing,whereby rotation of the clamping device relative tO the base plate andthe casing causes the device to clamp the base plate on said supportsurface.
 2. A distributor as claimed in claim 1 in which said supportsurface is in the form of a peripheral inwardly directed shoulderintegral with the casing.
 3. A distributor as claimed in claim 1 inwhich the surface of the casing engaged by the clamping device isdefined by part of a peripheral groove in the inner surface of thecasing.